The Experts below are selected from a list of 294 Experts worldwide ranked by ideXlab platform
Knut Erik Tollefsen - One of the best experts on this subject based on the ideXlab platform.
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acetylcholine esterase inhibitors in effluents from oil Production Platforms in the north sea
Aquatic Toxicology, 2012Co-Authors: Tor Fredrik Holth, Knut Erik TollefsenAbstract:Abstract Inhibition of acetylcholine esterase (AChE) activity is a biomarker for the exposure to neurotoxic compounds such as organophosphates and is intimately associated with the toxicity of several pesticides. In the present study, the AChE inhibiting potential of organic extracts of Production water (produced water) from oil and gas Production Platforms in the Norwegian sector of the North Sea was determined in an in vitro bioassay based on commercially available purified AChE from the electric organ of Electrophorus electricus (L.). The results from the studies show that produced water contains a combination of AChE inhibiting compounds and compounds stimulating AChE enzymatic activity. The AChE inhibition was predominantly caused by unidentified aromatic compounds in the oil/particulate fraction of produced water, whereas polar compounds in both the water soluble and oil/particulate fraction of produced water caused an apparent stimulation of AChE activity. Substrate saturation studies with fixed concentrations of produced water extracts confirmed that the inhibition occurred in a non-destructive and competitive manner. The concentrations of AChE inhibitors (7.9–453 ng paraoxon-equivalents L −1 , 2.2–178 μg dichlorvos-equivalents L −1 ) were in many cases found to be several orders of magnitude higher than background levels. The findings demonstrate that produced water contains potentially neurotoxic compounds and suggest that further laboratory studies with fish or field studies in the vicinity of oil Production facilities are highly warranted.
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produced water extracts from north sea oil Production Platforms result in cellular oxidative stress in a rainbow trout in vitro bioassay
Marine Pollution Bulletin, 2010Co-Authors: Christopher Harman, Eivind Farmen, Ketil Hylland, Knut Erik TollefsenAbstract:Abstract Produced water (PW) discharged from offshore oil industry contains chemicals known to contribute to different mechanisms of toxicity. The present study aimed to investigate oxidative stress and cytotoxicity in rainbow trout primary hepatocytes exposed to the water soluble and particulate organic fraction of PW from 10 different North Sea oil Production Platforms. The PW fractions caused a concentration-dependent increase in reactive oxygen species (ROS) after 1 h exposure, as well as changes in levels of total glutathione (tGSH) and cytotoxicity after 96 h. Interestingly, the water soluble organic compounds of PW were major contributors to oxidative stress and cytotoxicity, and effects was not correlated to the content of total oil in PW. Bioassay effects were only observed at high PW concentrations (3-fold concentrated), indicating that bioaccumulation needs to occur to cause similar short term toxic effects in wild fish.
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estrogen receptor er agonists and androgen receptor ar antagonists in effluents from norwegian north sea oil Production Platforms
Marine Pollution Bulletin, 2007Co-Authors: Knut Erik Tollefsen, Christopher Harman, Andrew Smith, Kevin V ThomasAbstract:Abstract The in vitro estrogen receptor (ER) agonist and androgen receptor (AR) antagonist potencies of offshore produced water effluents collected from the Norwegian Sector were determined using recombinant yeast estrogen and androgen screens. Solid phase extraction (SPE) concentrates of the effluents showed E2 agonist activities similar to those previously reported for the United Kingdom (UK) Continental Shelf ( −1 ). No activity was detected in the filtered oil droplets suggesting that produced water ER activity is primarily associated with the dissolved phase. Targeted analysis for methyl- to nonyl-substituted alkylphenol isomers show the occurrence of known ER agonists in the analysed samples. For the first time, AR antagonists were detected in both the dissolved and oil associated phase at concentrations of between 20 and 8000 μg of flutamide equivalents L −1 . The identity of the AR antagonists is unknown, however this represents a significant input into the marine environment of unknown compounds that exert a known biological effect. It is recommended that further analysis using techniques such as bioassay-directed analysis is performed to identify the compounds/groups of compounds that are responsible in order to improve the assessment of the risk posed by produced water discharges to the marine environment.
Joseph M. Suflita - One of the best experts on this subject based on the ideXlab platform.
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Design features of offshore oil Production Platforms influence their susceptibility to biocorrosion
Applied Microbiology and Biotechnology, 2017Co-Authors: Kathleen E Duncan, Irene A. Davidova, Heather S. Nunn, Blake W. Stamps, Bradley S. Stevenson, Pierre-jean Souquet, Joseph M. SuflitaAbstract:Offshore oil-producing Platforms are designed for efficient and cost-effective separation of oil from water. However, design features and operating practices may create conditions that promote the proliferation and spread of biocorrosive microorganisms. The microbial communities and their potential for metal corrosion were characterized for three oil Production Platforms that varied in their oil-water separation processes, fluid recycling practices, and history of microbially influenced corrosion (MIC). Microbial diversity was evaluated by 16S rRNA gene sequencing, and numbers of total bacteria, archaea, and sulfate-reducing bacteria (SRB) were estimated by qPCR. The rates of ^35S sulfate reduction assay (SRA) were measured as a proxy for metal biocorrosion potential. A variety of microorganisms common to oil Production facilities were found, but distinct communities were associated with the design of the platform and varied with different locations in the processing stream. Stagnant, lower temperature (
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design features of offshore oil Production Platforms influence their susceptibility to biocorrosion
Applied Microbiology and Biotechnology, 2017Co-Authors: Kathleen E Duncan, Irene A. Davidova, Heather S. Nunn, Blake W. Stamps, Bradley S. Stevenson, Pierre-jean Souquet, Joseph M. SuflitaAbstract:Offshore oil-producing Platforms are designed for efficient and cost-effective separation of oil from water. However, design features and operating practices may create conditions that promote the proliferation and spread of biocorrosive microorganisms. The microbial communities and their potential for metal corrosion were characterized for three oil Production Platforms that varied in their oil-water separation processes, fluid recycling practices, and history of microbially influenced corrosion (MIC). Microbial diversity was evaluated by 16S rRNA gene sequencing, and numbers of total bacteria, archaea, and sulfate-reducing bacteria (SRB) were estimated by qPCR. The rates of 35S sulfate reduction assay (SRA) were measured as a proxy for metal biocorrosion potential. A variety of microorganisms common to oil Production facilities were found, but distinct communities were associated with the design of the platform and varied with different locations in the processing stream. Stagnant, lower temperature (<37 °C) sites in all Platforms had more SRB and higher SRA compared to samples from sites with higher temperatures and flow rates. However, high (5 mmol L−1) levels of hydrogen sulfide and high numbers (107 mL−1) of SRB were found in only one platform. This platform alone contained large separation tanks with long retention times and recycled fluids from stagnant sites to the beginning of the oil separation train, thus promoting distribution of biocorrosive microorganisms. These findings tell us that tracking microbial sulfate-reducing activity and community composition on off-shore oil Production Platforms can be used to identify operational practices that inadvertently promote the proliferation, distribution, and activity of biocorrosive microorganisms.
Eivind Farmen - One of the best experts on this subject based on the ideXlab platform.
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produced water extracts from north sea oil Production Platforms result in cellular oxidative stress in a rainbow trout in vitro bioassay
Marine Pollution Bulletin, 2010Co-Authors: Christopher Harman, Eivind Farmen, Ketil Hylland, Knut Erik TollefsenAbstract:Abstract Produced water (PW) discharged from offshore oil industry contains chemicals known to contribute to different mechanisms of toxicity. The present study aimed to investigate oxidative stress and cytotoxicity in rainbow trout primary hepatocytes exposed to the water soluble and particulate organic fraction of PW from 10 different North Sea oil Production Platforms. The PW fractions caused a concentration-dependent increase in reactive oxygen species (ROS) after 1 h exposure, as well as changes in levels of total glutathione (tGSH) and cytotoxicity after 96 h. Interestingly, the water soluble organic compounds of PW were major contributors to oxidative stress and cytotoxicity, and effects was not correlated to the content of total oil in PW. Bioassay effects were only observed at high PW concentrations (3-fold concentrated), indicating that bioaccumulation needs to occur to cause similar short term toxic effects in wild fish.
Blake W. Stamps - One of the best experts on this subject based on the ideXlab platform.
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Design features of offshore oil Production Platforms influence their susceptibility to biocorrosion
Applied Microbiology and Biotechnology, 2017Co-Authors: Kathleen E Duncan, Irene A. Davidova, Heather S. Nunn, Blake W. Stamps, Bradley S. Stevenson, Pierre-jean Souquet, Joseph M. SuflitaAbstract:Offshore oil-producing Platforms are designed for efficient and cost-effective separation of oil from water. However, design features and operating practices may create conditions that promote the proliferation and spread of biocorrosive microorganisms. The microbial communities and their potential for metal corrosion were characterized for three oil Production Platforms that varied in their oil-water separation processes, fluid recycling practices, and history of microbially influenced corrosion (MIC). Microbial diversity was evaluated by 16S rRNA gene sequencing, and numbers of total bacteria, archaea, and sulfate-reducing bacteria (SRB) were estimated by qPCR. The rates of ^35S sulfate reduction assay (SRA) were measured as a proxy for metal biocorrosion potential. A variety of microorganisms common to oil Production facilities were found, but distinct communities were associated with the design of the platform and varied with different locations in the processing stream. Stagnant, lower temperature (
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design features of offshore oil Production Platforms influence their susceptibility to biocorrosion
Applied Microbiology and Biotechnology, 2017Co-Authors: Kathleen E Duncan, Irene A. Davidova, Heather S. Nunn, Blake W. Stamps, Bradley S. Stevenson, Pierre-jean Souquet, Joseph M. SuflitaAbstract:Offshore oil-producing Platforms are designed for efficient and cost-effective separation of oil from water. However, design features and operating practices may create conditions that promote the proliferation and spread of biocorrosive microorganisms. The microbial communities and their potential for metal corrosion were characterized for three oil Production Platforms that varied in their oil-water separation processes, fluid recycling practices, and history of microbially influenced corrosion (MIC). Microbial diversity was evaluated by 16S rRNA gene sequencing, and numbers of total bacteria, archaea, and sulfate-reducing bacteria (SRB) were estimated by qPCR. The rates of 35S sulfate reduction assay (SRA) were measured as a proxy for metal biocorrosion potential. A variety of microorganisms common to oil Production facilities were found, but distinct communities were associated with the design of the platform and varied with different locations in the processing stream. Stagnant, lower temperature (<37 °C) sites in all Platforms had more SRB and higher SRA compared to samples from sites with higher temperatures and flow rates. However, high (5 mmol L−1) levels of hydrogen sulfide and high numbers (107 mL−1) of SRB were found in only one platform. This platform alone contained large separation tanks with long retention times and recycled fluids from stagnant sites to the beginning of the oil separation train, thus promoting distribution of biocorrosive microorganisms. These findings tell us that tracking microbial sulfate-reducing activity and community composition on off-shore oil Production Platforms can be used to identify operational practices that inadvertently promote the proliferation, distribution, and activity of biocorrosive microorganisms.
Kathleen E Duncan - One of the best experts on this subject based on the ideXlab platform.
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Design features of offshore oil Production Platforms influence their susceptibility to biocorrosion
Applied Microbiology and Biotechnology, 2017Co-Authors: Kathleen E Duncan, Irene A. Davidova, Heather S. Nunn, Blake W. Stamps, Bradley S. Stevenson, Pierre-jean Souquet, Joseph M. SuflitaAbstract:Offshore oil-producing Platforms are designed for efficient and cost-effective separation of oil from water. However, design features and operating practices may create conditions that promote the proliferation and spread of biocorrosive microorganisms. The microbial communities and their potential for metal corrosion were characterized for three oil Production Platforms that varied in their oil-water separation processes, fluid recycling practices, and history of microbially influenced corrosion (MIC). Microbial diversity was evaluated by 16S rRNA gene sequencing, and numbers of total bacteria, archaea, and sulfate-reducing bacteria (SRB) were estimated by qPCR. The rates of ^35S sulfate reduction assay (SRA) were measured as a proxy for metal biocorrosion potential. A variety of microorganisms common to oil Production facilities were found, but distinct communities were associated with the design of the platform and varied with different locations in the processing stream. Stagnant, lower temperature (
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design features of offshore oil Production Platforms influence their susceptibility to biocorrosion
Applied Microbiology and Biotechnology, 2017Co-Authors: Kathleen E Duncan, Irene A. Davidova, Heather S. Nunn, Blake W. Stamps, Bradley S. Stevenson, Pierre-jean Souquet, Joseph M. SuflitaAbstract:Offshore oil-producing Platforms are designed for efficient and cost-effective separation of oil from water. However, design features and operating practices may create conditions that promote the proliferation and spread of biocorrosive microorganisms. The microbial communities and their potential for metal corrosion were characterized for three oil Production Platforms that varied in their oil-water separation processes, fluid recycling practices, and history of microbially influenced corrosion (MIC). Microbial diversity was evaluated by 16S rRNA gene sequencing, and numbers of total bacteria, archaea, and sulfate-reducing bacteria (SRB) were estimated by qPCR. The rates of 35S sulfate reduction assay (SRA) were measured as a proxy for metal biocorrosion potential. A variety of microorganisms common to oil Production facilities were found, but distinct communities were associated with the design of the platform and varied with different locations in the processing stream. Stagnant, lower temperature (<37 °C) sites in all Platforms had more SRB and higher SRA compared to samples from sites with higher temperatures and flow rates. However, high (5 mmol L−1) levels of hydrogen sulfide and high numbers (107 mL−1) of SRB were found in only one platform. This platform alone contained large separation tanks with long retention times and recycled fluids from stagnant sites to the beginning of the oil separation train, thus promoting distribution of biocorrosive microorganisms. These findings tell us that tracking microbial sulfate-reducing activity and community composition on off-shore oil Production Platforms can be used to identify operational practices that inadvertently promote the proliferation, distribution, and activity of biocorrosive microorganisms.
